JPH09229069A - Thrust bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of seizure by providing a cut groove extending in the direction opposite to the collar slide surface of pad while being open to the inner circumferential side of the back of pads, and providing one or more oil discharge hole being communicated with the inside of groove and being open to the outer circumferential side of bearing in each cut groove. SOLUTION: A pad 1 is composed of an oil groove 9, a tapered part 21 adjacent thereto, and a land part 22 adjacent to thereto. A cut groove 25 having a semi-oval sectional shape is provided extending in the direction opposite to the collar slide surface of each pad 1 while being open to the inner circumferential side of load side thrust bearing 7 behind each pad 1. Oil discharge holes 26, 26' are provided to penetrate the inner circumferential side surface downstream of the groove 25 and extends to the outer circumferential surface of outer circumferential side shroud 24. The groove 25 expands downstream and shrinks just before a next pad, and centrifugal force and resisting pressure act on lubricant thereat so that it is liable to flow to the outer circumferential side through oil discharge holes 26, 26'. The hole 26 positioned behind the land part 22 cools the vicinity of the land 22 and oil in the groove 25 cools the pad from tehback, thereby preventing generation of seizure in the bearing.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a thrust bearing device used for a supercharger or the like.

[0002]

2. Description of the Related Art FIG. 5 is a vertical sectional view of a conventional taper land type thrust bearing device, and FIG. 6 is a plan view of the thrust bearing, which is a sectional view taken along line VI-VI of FIG. In the figure, a collar 4 is fixed to a rotary shaft 1 via a spacer 2 and a tightening nut 3. A bearing mounting jig 6 is attached to the casing 5, a load side thrust bearing 7 is fixed to the bearing mounting jig 6, and a soft metal, for example, white metal 8 is cast on the surface in sliding contact with the collar 4. It is worn. An inclined taper portion and a land portion parallel to the sliding contact partner surface are formed on the sliding contact surface of the white metal 8 with the collar 4. An oil groove 9 is formed in a portion where there is no white metal between one set of taper portion / land portion and the adjacent set of taper portion / land portion. A portion including an oil groove, a taper portion adjacent to the oil groove, and a land portion adjacent to the oil groove is collectively referred to as one pad. The pad is the name of the portion formed as described above. Plural pads are formed on the collar side of the thrust bearing 7.

Lubricating oil is supplied to the oil groove 9 of the load side thrust bearing 7 through an oil supply hole 10. The lubricating oil that has passed through the oil supply hole 10 enters a circumferential oil groove 12 provided on the outer peripheral portion of the load side thrust bearing 7, and further passes through oil supply holes 13 that are formed at the positions corresponding to the respective pads of the thrust bearing. Then, it passes through the nozzle portion 14 and enters the oil groove 9. Lubricating oil leaked toward the inner peripheral side of the load side thrust bearing 7 is stored in the space 15
And is discharged from an oil drain hole (not shown). An oil drainer 16 is fixed to the bearing mounting jig 6 to prevent the lubricating oil from leaking out of the machine. An anti-load side thrust bearing 17 is fixed to the casing 5, and a white metal 18 is cast on the surface in sliding contact with the collar 4. An oil supply hole 2 is provided in the oil groove 19 of the anti-load side thrust bearing 17.
Lubricating oil is supplied via 0.

FIG. 6 is a plan view of the load side thrust bearing 7. The lubricating oil that has entered the oil groove 9 from the nozzle portion 14 flows to the taper portion 21 and reaches the land portion 22, and the fluid dynamic pressure is generated by the wedge action between them to generate the load capacity. Taper part 21
An inner peripheral shroud 23 is provided on the inner peripheral side and an outer peripheral shroud 24 is provided on the outer peripheral side to prevent the lubricating oil from leaking to the inner and outer peripheries and lowering the fluid dynamic pressure.

In addition to the thrust bearing of the above type, a step land type thrust bearing structure is also used. this is,
The portion corresponding to the taper portion 21 is formed in parallel with the land portion 22, and the structure of the other portions is the same as that described above.

[0006]

In the conventional step land type thrust bearing device, (1) the lubricating oil supplied from the oil groove 9 of the load side thrust bearing 7 reaches the land portion 22 from the taper portion 21. Shear is generated in the small clearance and heat is generated, so that the land portion 22 in particular becomes hot. When the temperature rises, the viscosity of the lubricating oil decreases, the thickness of the oil film formed decreases, and direct contact with the collar 4 occurs under high speed and high load conditions, causing damage. (2) The lubricating oil that has entered the taper portion 21 from the oil groove 9 receives centrifugal force due to viscous friction due to the high-speed rotating collar 4,
It becomes easier to flow toward the outer peripheral portion. Therefore, the flow rate of the lubricating oil decreases on the inner peripheral side of the taper portion 21 and the land portion 22,
Cooling capacity decreases and temperature rises higher. (3) A part of the lubricating oil whose pressure has become high due to the wedge action in the tapered portion 21 flows out to the inner peripheral side of the bearing through the inner peripheral shroud portion 23, and the load that is stationary with the rotating spacer 2 It flows through the clearance of the inner peripheral portion of the side bearing and reaches the space portion 15.
In the meantime, the viscous friction causes the lubricating oil to have a high temperature, and as a result, the inner peripheral portion of the load side thrust bearing 7 has a high temperature.

Due to each of the above causes, the inner peripheral side of the taper portion and the land portion becomes hot and damage such as seizure occurs. A similar problem occurs in the step land type thrust bearing.
The present invention is intended to solve the above-mentioned drawbacks of the prior art and prevent seizure of the inner peripheral portion of the thrust bearing.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is a collar fixed to a rotating shaft and rotating with the rotating shaft, and a taper land type or step land type slidingly contacting an end face of the collar. A thrust bearing device comprising a plurality of pads and a ring-shaped thrust bearing as a whole, in the thrust bearing device, the collar sliding contact surface of each of the pads is opened on the inner peripheral side of the position behind each of the pads of the thrust bearing. A notch groove extending in the opposite direction to each pad is provided corresponding to each pad, and one oil drain hole communicating with the inside of each notch groove and opening to the outer peripheral side of the thrust bearing is provided for each notch groove. The present invention relates to a thrust bearing device having the features described above.

[0009]

1 is a plan view of a thrust bearing device according to an embodiment of the present invention, and FIGS. 2, 3 and 4 are II-II, III-III and IV-IV of FIG. 1, respectively. FIG.
In the figure, reference numeral 25 denotes a notch groove having a semi-elliptical cross section, which is open to the inner peripheral side of the load side thrust bearing 7 behind each pad and extends in the direction opposite to the collar sliding contact surface of each pad. An oil drain hole that penetrates from the inner peripheral side surface on the wake side of each notch groove 25 to the outer peripheral surface of the outer peripheral side shroud portion 24. The configuration of other parts is the same as that of the related art.
The present invention can be applied to both taper land type thrust bearings and step land type thrust bearings.

The following actions and effects occur in this device. (1) By providing a notch groove in the thrust bearing corresponding to each pad, the conventional narrow gap between the spacer and the inner circumference of the bearing is widened, the viscous friction force is reduced, and the temperature rise of the lubricating oil is increased. Will be reduced. (2) The notch groove expands on the wake side and is squeezed just before the next pad, so that the lubricating oil flowing in the notch groove is subjected to a centrifugal force and damming pressure, and the lubricating oil flows from the drain hole. It becomes easy to flow to the outer peripheral side. Since the oil drain hole 26 is located behind the land portion where the temperature easily rises, oil flows to cool the vicinity of the land portion. Also, the oil in the notch groove cools the pad from behind. (3) By providing the notch groove in the vicinity of the land portion on the inner peripheral side where the temperature rise is high, the amount of thermal expansion in the axial direction of the thrust bearing can be reduced, and the contact on the inner peripheral side due to thermal expansion becomes stronger. Can be prevented.

By the actions and effects described in the above (1), (2) and (3), the temperature rise on the inner peripheral side and the land side of the bearing can be reduced, a stable oil film is formed, and the reliability of the bearing is improved. improves.

[0012]

According to the thrust bearing device of the present invention,
Corresponding to each pad, a notch groove that opens in the inner peripheral side of the position behind each pad of the thrust bearing and extends in the direction opposite to the collar sliding contact surface of each pad is provided inside the notch groove. Since at least one oil drain hole communicating with the thrust bearing and opening to the outer peripheral side of the thrust bearing is provided for each notch groove, seizure of the inner peripheral portion of the thrust bearing can be prevented.

[Brief description of drawings]

FIG. 1 is a plan view of a thrust bearing according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a vertical cross-sectional view of a conventional taper land type thrust bearing device.

FIG. 6 is a plan view of the thrust bearing (view taken along the line VI-VI in FIG. 5).

[Explanation of symbols]

 1 rotary shaft 2 spacer 3 tightening nut 4 collar 5 casing 6 bearing mounting jig 7 load side thrust bearing 8 white metal 9 oil groove 10 oil supply hole 12 circumferential oil groove 13 oil supply hole 14 nozzle part 15 space part 16 oil cut 17 anti Load side thrust bearing 18 White metal 19 Oil groove 20 Oil supply hole 21 Tapered portion 22 Land portion 23 Inner peripheral shroud 24 Outer peripheral shroud 25 Notched groove 26, 26 'Oil drain hole

Claims (1)

[Claims] 1. A thrust bearing which is fixed to a rotary shaft and rotates together with the rotary shaft, and a thrust bearing which has a plurality of taper land type or step land type pads slidably contacting an end face of the same color and has a ring shape as a whole. In the thrust bearing device described above, a notch groove that opens on the inner peripheral side of the position behind each pad of the thrust bearing and that extends in the direction opposite to the collar sliding contact surface of each pad is provided for each pad. A thrust bearing device, characterized in that at least one oil drain hole communicating with the inside of each of the cutout grooves and opening to the outer peripheral side of the thrust bearing is provided for each of the cutout grooves.